package com.agriculture.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.agriculture.common.CustomException;
import com.agriculture.entity.Category;
import com.agriculture.entity.Good;
import com.agriculture.mapper.CategoryMapper;
import com.agriculture.service.CategoryService;
import com.agriculture.service.GoodService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class CategoryServiceImpl extends ServiceImpl<CategoryMapper,Category> implements CategoryService{

    @Autowired
    private GoodService goodService;

    /**
     * 根据id删除分类，删除之前需要进行判断
     * @param id
     */
    @Override
    public void remove(Long id) {
        LambdaQueryWrapper<Good> goodLambdaQueryWrapper = new LambdaQueryWrapper<>();
        //添加查询条件，根据分类id进行查询
        goodLambdaQueryWrapper.eq(Good::getCategoryId,id);
        long count1 = goodService.count(goodLambdaQueryWrapper);

        //查询当前分类是否关联了菜品，如果已经关联，抛出一个业务异常
        if(count1 > 0){
            //已经关联菜品，抛出一个业务异常
            throw new CustomException("当前分类下关联了商品，不能删除");
        }

        //正常删除分类
        super.removeById(id);
    }
}
